FIG. 1 represents, in cross section, the anterior part of an eyeball inside which an implant 10 of this type is placed.
As the figure shows, posterior chamber 5 is limited in front by iris 4 and in the back by ciliary body 7 and crystalline lens 6.
The anterior part of the eye further comprises cornea 1, pupil 2 and iris 4 delimiting between themselves anterior chamber 3.
As indicated above, intracapsular posterior chamber implant 10 is put in place inside the capsule, i.e., the investing membrane 6 of the crystalline lens, the latter being removed.
Implant 10 of known type, represented in cross section in FIG. 1, and in plan in FIG. 2, consists of central part 11 forming the lens itself and support part 12.
Central part is biconvex (cf. FIG. 2) and the support part consists of circular crown 13 coaxial with central part 11 and connected to the latter by two "bridges" located along the same diameter.
The circular shape of support part 12 of this implant makes possible a good centering of the latter in the posterior chamber of the eye.
Further, the annularly shaped space delimited between support crown 13 and central part 11 of the implant allows a better attachment of the latter in the capsule of the crystalline lens by "welding" between the two walls 6a, 6b of this capsule.
However, this implant has certain drawbacks. Actually, the presence of two diametral bridges gives it a certain rigidity not facilitating its placement.
Further, its biconvex shape favors the adherence to its two faces of the walls of the capsule of the crystalline lens. Because of this, in the case of secondary cataract, i.e., of the growth of cells opacifying the capsule of the crystalline lens after removal of the latter, the laser radiation used to destroy these cells also damages the surface of the lens to which they adhere.